Two conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 2.0 mm. Conductor B is a hollow tube of outside diameter 2.0 mm and inside diameter 1.0 mm. What is the resistance ratio RA/RB, measured between their ends

Therefore,

The resistance ratio RA/RB, measured between their ends is

Explanation:

Given:

Consider Two conductors are made of the same material (A & B)and have the same length.,

Diameters,

Radius is half of Diameter,

Therefore  

To Find:

  (resistance ratio)

Solution:

Resistance for long wire with a Area of cross section is given by

Where,

R = Resistance

l= length

A = Area of cross section = πr²

i.e

When

material and length is same then Resistance is inversely proportional to Area,

Hence,

And

Equating we get

Substituting the values we get

Therefore,

The resistance ratio RA/RB, measured between their ends is

the answer would be c

f is prop to m1xm2 double m1 double force